In many electronic applications, particularly in automotive applications, power and logic devices are used in conjunction with each other, to perform a single function.
For example, an electric motor for operating an automatic sunroof or a window of a vehicle is typically actuated by a high-sided switch formed by power transistors. In order to reduce power consumption, the high-sided switch is ideally placed as close as possible to the electric motor, thus keeping the length of high current paths to a minimum and hence reducing unnecessary power losses.
Typically the driver of a vehicle may prefer to operate a separate switch on the dashboard of the vehicle, which then sends a (low-power) signal to the high-sided switch, in order to actuate it. Therefore a certain amount of logic circuitry is required, preferably at the high-sided switch, in order to control the actuation and other ancillary functions, such as fail-safe features.
Therefore there is a need to incorporate logic integrated circuits and power transistors into a single package module, which is ideally adapted to be mounted on or in close proximity to the electric motor.
A problem with existing combined logic/power packages is that the high power requirements of the high-sided switch do not easily facilitate integration with low power logic integrated circuits. The high currents involved preclude the use of conventional wire bond techniques, and the thermal management of heat dissipation presents further problems.
This invention seeks to provide an electronic package assembly which mitigates the above mentioned disadvantages.